major lexical category
【正确答案】：Major lexical categories are open categories in the sense that new words are constantly added. English has four major lexical categories, which are noun, main verb, adjective and adverb.
(P72)：语言中的词分为主要词类和次要词类。主要词类属于开放性词类,可以不断地纳入新词;次要词类属封闭性词类,这些词类中词的数量是固定的,不能添加新词。英语中有4种主要词类和6种次要词类,主要词类有名词、动词、形容词、副词。次要词类有限定词、助动词、介词、代词、连词、感叹词。